JPH05246545A - Method and system for automatic pickup - Google Patents

Abstract

PURPOSE: To provide a quick and sure operation with no assistance from an operator, related to a system and method for automatic pickup wherein a robot which, with a gripping member, comprises a joint-connected-arm controlled by a control part automatically picks up an object. CONSTITUTION: A robot 6 comprising, with a gripping member 8 for gripping an object, a joint-connected-arm 7 controlled by a control device 3 is provided. Here, the gripping member provides a camera 11 for generating a sensed image of at least a part of an object, with the sensed image comprising multiple dots, and the control device is provided with an image processing device 20 where the detected image is accepted and the coordinate of a specified point for it is determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic hoisting system and an automatic hoisting method for automatically hoisting an object by a robot having an articulating arm controlled by a controller together with a grip member.

[0002]

BACKGROUND OF THE INVENTION Manufacturing and packaging plants which employ reels of elongated material such as paper, plastic films, foils and the like, are very heavy and usually of varying width in different areas of the plant. It must supply multiple reels at the same time.

To this end, mobile robots are currently employed. The mobile robot hoists the reels from the loading position (pallet), loads them on a stand integrated with the robot, and moves them to the loading device of the plant.

In order to grab the reel when moving it from the loading position to the stand and from the stand to the loading device of the plant, the robot features an articulating arm with a circular gripping member at the end that holds the reel by vacuum. There is. Due to the wide variation in the inner and / or outer diameters of the reels used in complex plants, the available suction part of the circular gripping member is ring-shaped, its outer and inner diameters respectively being the smallest of the reels. Equal to outer diameter and maximum inner diameter.

[0005]

In order for the reel to be properly gripped by the articulated arm, the gripping member must be centered corresponding to the type of reel to be lifted, and the reel coordinates in the loading position are rare. Not exactly known to. And no preparation is made to help the operator, and it is necessary to provide the gripping member with an automatic centering system.

The present invention has been made under the above circumstances, and an object of the present invention is an automatic hoisting system and an automatic hoisting method for automatically hoisting an object by a robot having an articulating arm controlled by a control unit together with a gripping member. Therefore, it is an object of the present invention to provide an automatic hoisting system and an automatic hoisting method that can operate quickly and surely without the need of the operator's assistance.

[0007]

In order to solve the above-mentioned object of the present invention, an automatic lifting system according to the present invention comprises: an articulated joint controlled by a control unit with a gripping member for gripping an object. A robot having an arm; a gripping member providing optical means for creating a sensed image of at least a portion of the object, the sensed image being composed of a number of dots; and controlling The unit comprises processing means for receiving the detected image and determining the coordinates of a predetermined point of the detected image;

In such an automatic lifting system, the optical means provided by the gripping member creates a sensed image of at least a portion of the object with multiple dots.
Then, the processing means included in the control unit for controlling the articulated arm with the grasping member for grasping the object of the robot accepts the detected image and determines the coordinates of a predetermined point of the detected image.

In order to solve the above-mentioned object of the present invention, the automatic hoisting method according to the present invention is: Automatically hoisting an object by a robot having an articulating arm controlled by a controller with a gripping member. A method of creating a sensed image of at least a portion of an object by optical means on a gripping member, the sensed image being composed of a number of dots; and wherein the sensed image is sensed. The coordinates of a predetermined point of the image are determined by the control unit;

In such an automatic hoisting method, a plurality of dots create a detected image of at least a part of the object by the optical means on the gripping member associated with the articulated arm controlled by the controller of the robot, Then, the coordinates of the predetermined point of the detected image are determined by the control unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the automatic lifting system and the automatic lifting method of the present invention will be described in detail below. In FIG. 1, reference numeral 1 points to an automatic lifting system according to an embodiment of the invention.

The automatic hoisting system 1 comprises a vehicle 2 with a control unit 16 wirelessly connected to a plant supervisor 17. The vehicle 2, which is shown in more detail in FIG. 2, lifts the reel 4 in the loading position (not shown), places the reel 4 on one of the stands 5 on the vehicle 2, and then from the stand 5 to the reel 4. Is lifted and moved to the loading device (not shown) of the plant. To perform these tasks, the vehicle 2 provides a robot 6 having an articulating arm 7 with a circular gripping member 8 at its distal end, the reel gripping surface 9 of which is known in a known manner. An annular portion (not shown) is provided which is connected to a vacuum source (not shown) on the vehicle 2.

As shown schematically in FIG. 1, the reel gripping surface 9 of the gripping member 8 is also preferably centered on the reel gripping surface 9 inside the illuminator 10 and the annular portion. The camera 11 is provided.

The vehicle 2 is provided with a transmitter / receiver device 12 connected to a control device 16,
The control unit 16 connects the vehicle 2 to a plant supervisor 17 via antennas 13, 14 and a further transmitter / receiver unit 15, which supplies the control unit 16 with operating instructions and the nominal coordinates of the reel to be lifted. It

The control device 16 positions the articulated arm 7 above the nominal coordinates of the center of the hoisting reel 4 and is connected to the image processing device 20 via lines 23 and 24. The image processor 20 forms part of the controller 3 and receives information about the reel type via lines 23 and 24 and sends back the true coordinates of the center of the reel corrected relative to the nominal coordinates.

In order to accurately center the gripping member 8 with respect to the true coordinates of the center of the reel 4, the illustrated automatic lifting system 1 acquires an image of the central portion of the reel, including the central bore of the reel. It should be noted that this image is shown in the dark part in the image created by the camera and is sent to the control device 3. More specifically, it is sent to the image processing device 20 and processed by the image processing device 20 to determine the true coordinates of the center of the reel 4. This true coordinate is the articulated arm 7.
It is adopted by the numerical controller 16 for the control operation of.

The manner in which the images are processed by the image processing apparatus 20 is shown in FIG. 3 and FIG. 4 which shows a number of images resulting from the processing of the dot matrix that makes up the image created by the camera. However, I will explain from now on.

In connection with the above, the images quoted in the following description for clarity are created by the display of a dot matrix resulting from the processing of the image of the camera, even if it is not actually displayed. It

As shown in FIG. 3, first in block 30, the image processor 20 acquires an image created by a camera and composed of multiple dots. Each is characterized by a count value that is proportional to the brightness of the dots in the portion captured by the camera, for example the maximum (eg 255) and minimum corresponding to the “white” and “black” levels. It consists of a whole number spanning values (usually 0).

Next, in block 31, a histogram of the values of the dots in the image is calculated, where the individual counts are related by their value to the number of dots. Then, on the basis of the histogram, block 32 distinguishes between very bright dots, which do not clearly form the central axis hole portion of the reel, and dark dots, which can form the axial hole portion. A threshold value for

In block 33, the dots in the image created by the camera 11 are compared with the threshold determined in block 32 to determine whether the individual dots are binary values above or below the threshold. Logical value (lo
gic value) is assigned.

For example, a dot whose brightness (ie, count value) is above the threshold is assigned a logical value of "0", and a dark dot is assigned a logical value of "1". These logical values are stored in a memory device, such as a memory array.

The image resulting from such processing is hereinafter referred to as a reference image for simplification, and as shown in FIG. 4A, dots of logic "0" and "1" are white. And become black.

The image in FIG. 4A shows a dark main portion corresponding to the reel bore and a number of background noise portions due to, for example, imperfect flatness of the reel sides and other factors. As a result, some parts of the reel appear darker than others. The above image also shows other parts unrelated to the reel (eg part of the support pallet)
Is included.

Next, in block 34, an inverted image consisting of dots with logical values that are either shaded or inverted compared to the reference image dots is created, the result of which is shown in FIG. A negative image is created.

In block 35, the inverted image is shifted in the first direction, for example to the right, by a predetermined distance Ds as shown in FIG. 4C, and for simplicity the dark background is shown in FIG. 4C. Only the outline of the upper bright part is shown.

At block 36, an AND operation is performed with the reference image dot (FIG. 4A) and the corresponding dot in the inverted and shifted image (FIG. 4C), and this operation is renewed. A new image or matrix, and the dots of the new image or matrix are such that when the corresponding dots in both the reference image and the inverted and shifted image display a logical "1" value, ie in the case of the problem Displays a logical "1" value only when both are black.

In order to make this clearer, (D) of FIG.
Then, the solid line is in the reference image of FIG. 4A (on a white background).
A black dot portion is shown and a broken line shows a white dot portion (on a black background) in the inverted and shifted image of FIG. 4C, which is the result of the AND operation described above, a logical "1". FIG. 4 showing the outline of the (black) dot portion.
(E) of.

In block 37, the dot in the image thus formed ((E) in FIG. 4) is the known radius of the central axis hole of the reel 4 minus 1/2 of the distance Ds. Shifted in the same direction as before by a distance Ds1 to give a dot matrix corresponding to the image shown in FIG. The image shown in FIG. 4 (F) is referred to below as the cross image.

The operations performed in blocks 35, 36 and 37 are repeated three or more times, each time shifting the negative image (FIG. 4B) by the same distance Ds in different directions. The individual crossing images are shifted in the same direction by a distance Ds1. The steps described above with respect to the matter in question are shown in FIGS. 4 (G), (H), (I), (J), (K).

FIG. 4G shows the image from the result of overlapping the reference image with the image created by shifting the negative image upwards by the distance Ds. More specifically, the solid outline points out the black dots (on a white background) in the reference image, and the dashed outline is inverted and the white dots (on a black background) in the image shifted up. Point out the part.

The AND operation creates a dot matrix corresponding to the image (intersection image) shown in FIG. 4H and shows the outline of the black dot portion on the white background. 4I shows an image which is a result of shifting the image of FIG. 4H upward by the distance Ds1.

Similarly, FIG. 4 (J) shifts the inverted image of FIG. 4 (B) by a distance Ds, and the shifted and inverted image and the reference image of FIG. 4 (A). It shows an intersection image created by a dot matrix by performing an AND operation and shifting the resulting image to the left by a distance Ds1. Similarly, FIG. 4 (K) shows the crossed image from the result of the downward shift.

Following the above described operation (ie, the output of block 38 of FIG. 3), the method in accordance with the present invention, in block 39 of FIG. 3, produces four crossed images (FIG. 4) as shown in FIG. (F), (I), (J), (K)) are crossed. FIG. 4L shows the outline of the logical "1" dot portion of the four crossed images. For the sake of simplicity, the dark noise part is omitted from FIG. 4L and is removed in the crossing operation because it does not overlap in the four-direction shift described above.

The resulting intersection (which is again affected by ANDing the logical values of the dots in the four intersection images) is a small central square or other with the actual center of the reel inside. Create small irregular shapes.

In accordance with the method of the present invention, block 40 then determines the coordinates of the center of the rectangle to provide the theoretical center coordinates of the reel. Then, in order to further increase the precision, in the block 41, in the reference image,
2 along two perpendiculars that pass through a theoretical center that is predetermined on the perimeter of the dark area within which the quadrangle lies
Determine the point of the pair. Thanks to the peripheral symmetry, the two waypoints of the two pairs of points create a further evaluation of the reel center (block 42).

This completes the determination of the reel center coordinates,
The determined center coordinates of the reels are then read by the image processing device 20.
By means of a line 24 to a numerical control device 16, which further creates a further control of the articulating arm 7 to effect a centering of the gripping member 8 with respect to the reel 4, and then the gripping member 8 is known. It is lowered on the reel by the method of.

The gripping member 8 is therefore perfectly centered with respect to the reel 4 at any time, independent of the lighting conditions and any noise in the sensed image, and thus without the need for any assistance from the operator. This enables quick and sufficient automatic transfer of the reel 4 from the pallet) to the stand 5.

Even if regular, the coordinates of a particular predetermined point can be determined by detecting the center of an object of different shape, for example a quadrilateral object, or by appropriately selecting the amount of shift to be affected. It has to be pointed out that the same method as described above can be used for this.

[0040]

As described in detail above, the automatic hoisting system and the hoisting method of the present invention are an automatic hoisting system for automatically hoisting an object by a robot having an articulating arm controlled by a control unit together with a gripping member. Also, it is an automatic hoisting method, and it can operate quickly and surely without requiring the assistance of the operator.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a configuration of an automatic hoisting system according to an embodiment of the present invention.

FIG. 2 is a schematic external view of the apparatus of FIG.

3 is a schematic flow chart of an automatic hoisting method by the apparatus of FIG.

4 (A), (B), (C), (D), (E),
(F), (G), (H), (I), (J), (K),
(L), (M) is a figure which shows schematically the various steps which determine the center of the object to be lifted along the flow chart of FIG.

[Explanation of symbols]

1 ... Automatic lifting system, 2 ... Vehicle, 3 ... Control device,
4 ... Reel, 5 ... Stand, 6 ... Robot, 7 ... Articulated arm, 8 ... Gripping member, 9 ... Reel gripping surface, 10 ... Illumination device, 11 ... Camera, 12 ... Transmitter / Receiver device, 13, 14 ... Antenna , 15 ... Transmitter
Receiver device, 16 ... Control device, 17 ... Plant supervisor, 20 ... Image processing device, 23, 24 ... Line.

Front page continuation (72) Inventor Giuseppe di Stefano Italy, 44100 Ferrara, Via Marconi 188 (72) Inventor Armando Neri Italy, 40100 Bologna, Via Naples 7

Claims (22)

[Claims] 1. A robot (6) comprising an articulating arm (7) controlled by a controller (3) with a gripping member (8) for gripping an object (4); (8) provides optical means (11) for creating a sensed image of at least a portion of the object, the sensed image being composed of a number of dots; and a controller (3) An automatic lifting system, comprising: processing means (20) for receiving the detected image and determining the coordinates of a predetermined point of the detected image. 2. Means (34, 35, 36, 3) for the processing means (20) to create at least second and third images.
7), each of the second and third images consisting of a number of dots shifted with respect to a number of dots of the detected image, the processing means (20) also comprising the detected image, the number of dots Automatic lifting system according to claim 1, characterized in that it comprises crossing means (39) for determining a dot common to the second and third images. 3. The dot is characterized by a count value that is proportional to the brightness of the dots in the portion and spans a minimum value and a maximum value, and a processing means (20) further comprises: Comparing means (31, 32, 33) for comparing a numerical value with a threshold value and creating a reference matrix containing a large number of dots having a logical binary value. The automatic lifting system described in 2. 4. Comparing means (31, 32, 33), means (31) for determining the relative frequency of dot count values, and means (32) for creating a threshold value based on the relative frequency.
The automatic lifting system according to claim 3, further comprising: 5. The processing means (20) comprises a comparison means (31,
32, 33) downstream of (32, 33) and comprising inversion means (34) for creating an inverted matrix containing a number of dots having an inverted binary value as compared to the corresponding dot in the reference matrix. The automatic lifting system according to claim 3 or 4, characterized in that. 6. The processing means (20) comprises a reversing means (34).
A first shift provided downstream of to effect a first shift of the dots in the inverted matrix, thereby creating a plurality of first shifted matrices each containing a large number of dots. Automatic lifting system according to claim 5, characterized in that it comprises means (35), the multiple first shifts being influenced in different directions. 7. The processing means (20) each have a respective first
AND the corresponding binary values of the corresponding dots in the inverted matrix and the respective first shifted matrix located downstream of the shift means (35) to create respective intersecting dot matrices. 7. An automatic lifting system according to claim 6, characterized in that it comprises a number of multiplying means (36). 8. The processing means (20) comprises a plurality of second shifting means (37) each located downstream of the respective multiplying means (36) and the first shifting means (35). , Each of the second shifting means influences the second shift in the same direction as the first shift by the respective first shifting means, thereby relating to the corresponding dot in each crossing matrix. An automatic lifting system according to claim 7, characterized in that it creates a respective second shifted matrix comprising a large number of vertically shifted dots. 9. The processing means (20) is connected downstream of a number of second shifting means (37) and ANDs the binary values of the corresponding dots in every second shifted matrix. 9. An automatic lifting system according to claim 8, characterized in that it is manipulated to create a small matrix of dots having a predetermined binary value. 10. Processing means (20) for determining the coordinates of the center of said small dot matrix (40, 41, 42,
43) is provided, The automatic lifting system of Claim 9 characterized by the above-mentioned. 11. The center hole provides a predetermined radius for detecting the center of the center hole of an elongated reel of material (4), each of the first shifting means (35) having a predetermined direction. To create a first shift by an amount (Ds) equal to a fraction of the radius, and each of the second shifting means (37) performs a second shift by an amount (Ds1) slightly smaller than the predetermined radius. It creates, The automatic lifting system of any one of Claim 8 thru | or 10 characterized by the above-mentioned. 12. A method of automatically hoisting an object by a robot having an articulating arm controlled by a control unit together with a gripping member, wherein the detected image of at least a part of the object is obtained by an optical means on the gripping member. The step of forming the detected image by a large number of dots; and the coordinates of a predetermined point of the detected image being determined by the control unit. Automatic lifting method. 13. Providing at least a second and a third image are created, each of the second and third images comprising a number of dots shifted with respect to a dot of the detected image. And, a point common to the detected image, the second image, and the third image is determined here, The automatic lifting method according to claim 12, wherein. 14. The dot is characterized by a count value that is proportional to the brightness of the dots in the portion and that extends between a minimum value and a maximum value, and the coordinate determining step includes the count value. 14. The method of claim 12 or 13 further comprising the step of: comparing a threshold value to a threshold value to create a reference matrix containing a number of dots having two logical values. 15. The step of comparing the counts comprises:
The automatic hoisting method according to claim 14, further comprising a step of determining a relative frequency of the count value and creating the threshold value based on the relative frequency. 16. The method comprises the step of creating an inverted matrix comprising a number of dots having inverted binary values as compared to corresponding dots in the reference matrix. The automatic lifting method according to claim 14 or 15. 17. A plurality of first shifted matrices, each containing a plurality of dots, created by affecting a first shift of the dots in the inverted matrix in different directions. The automatic lifting method according to claim 16, further comprising a step of: 18. The method also comprises the step of ANDing the binary values of the dots in the inverted matrix and the respective first shifted matrix to create a number of intersecting dot matrices. The automatic lifting method according to claim 17, wherein: 19. A number of dots, each shifted in relation to a corresponding dot in a respective crossing matrix, in the same direction as the first shift of the respective first shifted matrix. 19. The automatic hoisting method of claim 18, further comprising the step of creating a plurality of included second shifted matrices. 20. An AND operation of the binary values of corresponding points in all said second shifted matrices is performed in order to create a small matrix of dots having two predetermined values. The automatic lifting method according to claim 19, further comprising: 21. The automatic hoisting method of claim 20, further comprising the step of determining the coordinates of the center of the small dot matrix. 22. To detect the center of a center hole of a reel of elongate material, the center hole provides a predetermined radius and the first shift is created by an amount equal to a fraction of the radius. And the step of creating the second shifted matrix,
20. The automatic hoisting method according to claim 19, comprising the step of creating a number of second shifts slightly smaller than the predetermined radius.